With temperatures reaching above 90 degrees for the fourth day in a row, a heat advisory remained in effect until 7 p.m. A heat advisory is issued when a prolonged periods of hot weather could create a situation where heat illnesses such as heat exhaustion and heat stroke are possible.

In Boston, the number of EMS calls for heat-related problems was significantly higher.

"We ask you to keep an eye on the elderly and the small children. They can't regulate heat as well," said Boston EMS Capt. Jose Archila.

Storm Team 5 meteorologist Mike Wankum said it was our second official heat wave of the summer of 2013.

“The pace of 90-plus days is very similar to the summer of 2010. That year we ended with a near record-setting 25 days above 90,” Wankum said.

The heat advisory would likely be reissued for Sunday afternoon, when Wankum said it would be our last day above 90 for the time being.

“It will still be hot and humid but with additional cloud cover expect highs topping out in the upper 80s. The only place that will remain relatively cool will be south-facing beaches and the Cape,” he said.

Despite the heat, Wankum said some areas of the state could see Sunday afternoon thunderstorms.

“The biggest concerns with these storms are lightning, gusty winds and torrential downpours. Not everyone will see these thunderstorms and it will be far from a washout,” he said.